This extract from the NSA’s Special Source Operations division’s weekly memo describes the operation of SCALAWAG, the SIGAD (or collection address) associated with the MYSTIC collection of bulk telephony data: see the Washington Post article NSA surveillance program reaches ‘into the past’ to retrieve, replay phone calls, 18 March 2014.

﻿(U) Tasking of SCALAWAG
(TS//SI//REL TO USA, FVEY) SCALAWAG/US-3310BG has long since
reached the point where it was collecting and sending home far more
than the bandwidth could handle. Over ...